COVID-19 Vaccine Effectiveness among Patients with Psoriatic Disease: A Population-Based Study.

Limited information is available on the effectiveness of COVID-19 vaccination in patients with psoriasis and psoriatic arthritis (psoriatic disease (PsD)). The objective of our research was to assess the effectiveness of mRNA COVID-19 vaccination in preventing SARS-CoV-2 positivity and severe infection in a cohort of patients with PsD and the association of immunosuppressants on SARS-CoV-2 infection-related outcomes from December 2020 to December 2021. Vaccine effectiveness was assessed in a matched nested case control study using conditional logistic regression adjusted for demographics, comorbidities and immunosuppressant use. Study outcomes included SARS-CoV-2 positivity and severe COVID-19 (moderate-to-severe COVID-19-related hospitalizations or death). At least one dose of mRNA COVID-19 vaccine was associated with reduced risk of SARS-CoV-2 positivity and severe COVID-19 (OR = 0.41 (95% CI, 0.38-0.43) and OR = 0.15 (95% CI, 0.11-0.20), respectively). A more significant effect was found among patients who received three vaccines doses compared with those who did not receive any (OR (for positive SARS-CoV-2) = 0.13 (95% CI, 0.12-0.15) and OR (for severe disease) = 0.02 (0.01-0.05)). Etanercept and methotrexate were associated with higher risk of SARS-CoV-2 positivity (1.58 (1.19-2.10), p = 0.001 and 1.25 (1.03-1.51), p = 0.03, respectively). In conclusion, our results show that mRNA COVID-19 vaccines are effective in reducing both infection and severe COVID-19-related outcomes.